Taiwan might have just unraveled its first ever Chinese spy case where the suspected Chinese agent has been posing as a student from the mainland. The case adds to the growing concern that the thousands of Chinese students pursuing education in Taiwan might constitute a greater national security risk than previously assumed.

In a statement Taiwanese prosecutors said that Zhou Hongxu, a Chinese man from Liaoning Province, who spent the last few years studying in Taiwan, was arrested on March 10 on suspicion of espionage for China.

Zhou was enrolled in Taiwan’s National Chengchi University’s MBA program from 2012 until 2016, when he graduated. National Chengchi University is noted in Taiwan for leaning politically toward the Kuomintang (KMT) party, which views China more favorably than the ruling Democratic Progressive Party (DPP).

According to Taiwanese media, publicly available content on Zhou’s Facebook profile documented his extensive networking over the past few years with Taiwanese students and a number of pro-China political figures in Taiwan. Zhou also made a number of political posts criticizing Taiwan’s politics, and participated in various political events and groups while there, even though Taiwan’s immigration law specifically forbids visa holders from engaging in public activity or work not related to the stated purpose of their visa.

Zhou returned to Taiwan in February 2017, this time under a business visa sponsored by a supposedly Hong-Kong based company Yongming Industry Co Ltd, according to Taiwan Minister of Justice Chiu Tai-san in testimony before the Taiwanese parliament.

Prosecutors said that Zhou attempted to recruit a Taiwanese official working for Taiwan’s Ministry of Foreign Affairs. Using popular Chinese messaging application WeChat, Zhou sent messages soliciting the official to reveal information concerning his work in exchange for cash, and even offered to meet in Japan for the exchange to take place. The official, however, reported Zhou to the authorities, which led to his arrest.

Students from mainland China have been allowed to study in Taiwan since 2009, when KMT President Ma Ying-jeou relaxed the restriction in the hope that more Chinese students will boost enrollment at Taiwan’s colleges and universities, while facilitating cross-strait educational and cultural exchanges. According to Taiwan’s Ministry of Education statistics in 2015, there were 7,813 mainland Chinese students in Taiwan enrolled in various degree programs, and another 34,114 came to Taiwan for short-term study.

Critics point out that China has a documented record of sending spies and agents of influence to Taiwan under a variety of covers, and the large number of mainland Chinese students in Taiwan pose a significant risk to Taiwan’s national security. Zhou’s case is notable for being the first case where the arrested suspect has been a mainland Chinese student in Taiwan.

Michael Tsai, a former Taiwan Minister of Defense, said that Zhou’s case reveals only the tip of the iceberg of China’s broader “United Front” warfare against Taiwan. China’s United Front, according to Tsai, seeks to systematically recruit and compromise certain segments of Taiwanese society so as to weaken Taiwan’s internal resistance to reunification with China.

“Chinese spies come into Taiwan not just as students, but also academics, scholars, businessmen, and even entertainment figures,” said Michael Tsai in a phone interview with The Epoch Times, “Our [Taiwanese] government needs to start reexamining the vetting process for mainland Chinese getting into our country.”

Paul Huang is a Master’s candidate at the Fletcher School of Law and Diplomacy, Tufts University, and is affiliated with the Taiwan edition of The Epoch Times.